Duplicating machine



Oct. 7, 1952 SHERMAN 2,612,834

- DUPLICATING MACHINE 2 SHEETS-SHEET 1 Filed Feb. 14 1950 INVENTOR. Herbert! P Sherman gar-WW1? Oct. 7, 1952 H. 'P.SHERMAN DUPLICATING MACHINE Filed Feb. 14, 1950 2' SHEETS -SHEET 2 ami" Patented Oct. 7, 1952 i257 '-My invention relates to an id in v of the type employing stencils ne mor e' particularly to improvements, in th 1nklng meansj thereof. I I Heretof ore, in duplicating machines described, the stencils were stretched supported on the face of a rotatable/(nu face of which was perforated overanar ea' suc stantially coextensive with that of theist'ericiland was covered with 'a fabric blanket against which the stencil was, placed. A duanti'ty of siiitable ink was introduced, through an opening, intdthe drum interior and; in thecourse'ofrotation' of the drum, the ink was caused to-pa ss'throiigli the perforations to wetthe fabric-blanket which'acte'd in the nature of a'wick to conducft theink;toitlie' stencil from which it was deposited wash ofpaper or the like; The foregoin'g'typeofstericihdruin hadcertain 'disadvantagesamong' whichwas' the constant escape of the ink; during theoperatiOn"oi -the machine, along the edges "of thfstencilq" This was, in the mainydue to tuefpressureor-a co operating roller 'agains't th'e drum 'which"tended to accumulate, immediately 7 in "advance of the a being on an enlarged scale. Fig; 3=isra"cross sectional view taken substan-a line of Contact of the roller with the drumfu'nde'rthe stencil, a -ma'ss of ink which-*i'ncreasedprogressivelyin "quantity with each increment-of rotation or the drum. Sinceno "satisfactory means was provided forth'e return of th'e' ink to:

the interior of the" drumgthe-ink escaped along ingabase structure H, a stencilcarrying drum,-

the edges ofthe stencil. Another disadvantage was the necessity for positioning the drumiinta' particular position when the machine was not in use so as to prevent the escape of ink through; the perforations in the drum. A furthen'disadvantage was the necessity for :cleaning the fabric blanket after each use sothat' the blanket would not become clogged with ink pigment and thereby impair the wickingactionfthereoii:.- 1:11

provide an improved drum constructionuin which is eliminated the use of a perforated; drumiace and a fabric wicking blanket stretched thereover,

and instead thereof, is provided 'a-drumrface formed of porous metal through whichthe-ink may pass by capillary action, to the stencil. Thus,- the plate of porous metal controls-the amount of ink contacting the stencil and preventsthe acof ink which.

surface of the stencil, resulting in reproductions which are allofuniiorm uality.

'40 Accordingly,it is an object of myinvention'to.

' the drum through expression "hf-still further object of my invention is the provision of a drum face which is easily cleaned" andjmore idu'rable than the fabric blankets of prior 'aitfd evices which require replacementat fr quen s-terms. m

A still'f-further object of my invention is' -tlie provision-of-animproved drum so constructed that "excessive ink is absorbed by an absorbent memberandj in the course of operation oi the machineg'the ink" is returned to the interio'r'pf of the ink from the absorbent member.

Other and further objects and advantages of my invention will become apparent from the following"des'cription when considered in connec-;

' tion with-the accompanying drawings in which:

Figs lis an elevational' view of a duplicating machine embodying my invention. Fig.2 is a" vertical cross sectional view taken substantially on line 2-2 of Fig. 1, the said view tially online 33'of Fig.2.

a Fig'zi l is a'fragmentary viewsimilar to Fig. 3'

but showing-the drum and pressure roller'in'an-- indicated-generally at [2, areciprocating pressure member 13 acting on the stack of sheetsjll to=efiect a displacement of only the topv sheet of the stack at; any one time, and a pressure roller:

l6,- springzbi ased, so as to exert an upward thrust;

and to engage the underside of a sheet'on which,

a reproduction is to be made to urge thesame against the stencil carried on the drum- I2.

.My'invention is directed specifically to the const'ructionf'of thedrum I2 and its manner of'op'er: atiogi. Referring particularly to Figs. 2 to 5 inclusive the drum of my invention is shown as, comprising dished end members I! and I8 foi identical construction, each being formed withan' annular flange I9, the end portion of which is reversely bent as at 2| in ofiset relation to the flange. l9 to-provide a space therebetween and is fur'ther bent upwardly to providea flange 22 in avertical plane. The end members I! and IBare formed-substantially as shown in elevation-in 23, for a purpose, as will be hereinafter described.

It is to be understood that the flange construction, above described and illustrated more clearly in Fig. 2, extends completely around the peripheral edges of the end members l1 and [8. The said members H and is are suitably mounted on a shaft 24 to rotate therewith, the said shaft being suitably journaled in end members 26 of the base II. A crank arm 27 is fixed to the-shaft '24 and is adapted for rotating the said shaft and with it the drum !2.

Supported on the flanges I8 and extending 1 substantially from point A to point B is a plate member 28, the said plate member being in the form of a metal sheet having a quality of porosity such that ink may pass therethrough. I have 42 within the recess 23. It will be apparent that slight movement of the retaining member 43, radially of the drum, thus, is possible because of the frictional engagement of the clips 44 with .the end members I! and I8.

found that a product manufactured by the Chrysler Corporation, Amplex Division and sold under the trade-mark of Oilite functions to produce highly desirable results. Thesaid material i abronze alloy which has been .processed according to methods well-known in. powder metallurgy. It is beunderstood, however, that my invention is not limited to the-use of the particular Oilite product but is directed-to the use of a metal sheet which has the desired porosity so that ink may pass therethrough, from one side to the other, tosupply ink to a stencil which is adapted to lie contiguous to the outer surface of the said plate.

A second imperforate plate member 29,,prefer ably of sheet metal is supported on the flange l9 and extends from points B through 0 to A so as to provide a continuous face with the member 28 for the drum [2. The marginal edgesxof the plate member 29, like those of the member 28, are received in the peripheral recesses of the end members I! and I8 and are sealed therewith, as with solder, to provide a water-tight joint. The plate member 29 follows the contour of themripheral edges of the recessed portions 23 of the end members I! and I8, as viewed in Fig. v3, sons to form a longitudinally extending trough in The operation of my device should be understood' from the foregoing description, but briefly blank sheet is effected in a well-known manner.

which is received the absorbent material herein- I after to be described. The trough is provided with an elongated slot or a plurality of apertures 30 for a purpose as will be hereinafter explained.

Attached to the plate member 29, as by rivets, is a strip 3| having struck out'from the plane thereof, a plurality of hook like elements 32 which are adapted to engage in the apertures provided at the end of stencil 25 to secure the same to the drum face. A substantially U-shaped member 33 is riveted to the face of the member 23 and is formed with a longitudinal portion 34. The said member preferably, is formed of a resilient metal and is arranged to bear against the surface of the member 29 and to secure the other end of the stencil 25 between the longitudinal portion 34 and the surface of the member 29. Thus, the stencil 25 is held securely and maintained in taut condition while on the drum. In order to facilitate insertion or removal of the end of the stencil from the drum, an L-shaped wire element 36 is provided, the said element having offset portions 31 which are adapted to engage under the legs of the U-shaped member 33 so that when the lever arm 38 of the wire element is moved, a camming action is effected which temporarily lifts the portion 34 from the surfaceof the plate member 29 so as to provide a space therebetween.

The drum l 2 is provided with a filling aperture 33 through which ink may be admitted intothe During the course of operation, as a result of the action of the cooperating roller l6 against the stencil 25, in each turn of the drum, a mas of ink mayaccumulatebetween the stencil 25 and the porous plate 23, the mass of ink increasing progressively in amount until the roller I6 reaches point-B adjacent the recess 23. At this point, the ink is caused to flow into the recess 23 and to be absorbed by the absorbent member 42. In the course of furtherrotation of the drum, after the absorbent. member has become saturated with ink,-the cooperating roller [6, in pressing against the said absorbentmember, acts to express the ink therefrom and to force the same through the: slot 30 in the recess 23, thereby returning the ink to the interior of the drum for further use. It-will thus be apparent that dripping of the ink from the drum is completely obviated, thereby resulting in a more economical and cleaner operation of the machine. I have found that a porous metal plate of the type described has the property of allowing just the right amount of ink topass through to the stencil to obtain a clear impression of the stencil on the paper.

I claim;

'1'. In a duplicating machine of the type described, a rotatable substantially cylindrical drum adapted to support a stencil, said drum comprising end members each having a substantially semicircular portion, an adjacent arcuate portion of progressively decreasing radius of curvature and a recessed portion connecting said twofirst mentioned portions, a porous plate through which ink may pass by capillary action arranged between said semi-cylindrical portions and constituting a portion of the face of said drum, a non-porous plate arranged between said arcuate and said recessed portions and constituting the-remainder of the face of said drum, said non-porous plate having an aperture therein aligned with said recessed portion, a mass of absorbentmaterial adjacent the face of said drum at said recessed portion, and means for securing a stencil-contiguousto said porous plate.

2. In a duplicating machine of the type described, a rotatable substantially cylindrical drum having a face one portion of which is substantially semi-circular in profile and of such porosity that ink may pass therethrough by capillary action, means for securing a stencil in contiguous relation to said face portion, said face having an adjacent non-porous portion which is arcuate in profile and of progressively decreasing radius of curvature, said face also having a recessed portion connecting said arcuate and semi-cylindrical portions, said recessed portion having an aperture therein, and a mass of absorbent material within said recessed portion.

3. In a duplicating machine of the type described, a rotatable substantially cylindrical closed drum adapted to contain ink therein and having a face a portion of which is of such porosity that ink may pass therethrough by capillary action, means for securing a stencil contiguous to said porous face portion, said drum having another face portion which is recessed inwardly to form a longitudinal trough, said trough having an aperture therein afiording communication with the interior of said'drum, and a mass of absorbent material supported in said recessed portion and adapted to absorb excess ink expressed from between said porous plate and said stencil.

4. In a duplicating machine of the type described, a rotatable substantially cylindrical,

closed drum adapted to contain ink therein and having a face a portion of which is of such porosity that ink may pass therethrough by capillary action, means for securing a stencil contiguous to said porous face portion, said drum hava ing another face portion which is recessed inwardly to form a longitudinal trough, said trough having an aperture therein affording communication with the interior of said drum, and a mass of absorbent material supported in said recessed portion and adapted to absorb excess ink expressed from between said porous plate and said stencil, and a roller cooperating with said drum to express ink from said absorbent mass through said aperture and into said drum.

5. In a duplicating machine of the type described, a rotatable substantially cylindrical drum having a face one portion of which is substantially semi-circular in profile and of such porosity that ink may pass therethrough by capillary action, means for securing a stencil in contiguous relation to said face portion, said face having an adjacent non-porous portion which is arcuate in profile and of progressively decreasing radius of curvature, said face also having a recessed portion connecting said arcuate and semicylindrical portions, said recessed portion having an aperture therein, and an absorbent member removably received within said trough, said absorbent member substantially filling said trough and being adapted to absorb excess ink expressed from between said porous plate and said stencil.

6. In a duplicating machine of the type described, a rotatable substantially cylindrical closed drum adapted to contain ink therein and having a face a portion of which is of such porosity that ink may pass therethrough by capillary action, means for securing a stencil contiguous to said porous faced portion, said drum having another face portion which is recessed inwardly to form a longitudinal trough, said trough having an aperture therein afiording communication with the interior of said drum, an absorbent member removably received within said trough, said absorbent member substantially filling said trough and being adapted to absorb excess ink expressed from between said porous plate and said stencil, and a roller cooperating with said drum to express ink from said absorbent member through said aperture and into said drum.

HERBERT P. SHERMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Iiumber Name Date 2,022,539 Elliott Nov. 26, 1935 2,102,541 Osborn Dec. 21, 1937 2,319,616 Luehrs May 18, 1943 2,468,400 Hueber Apr. 26, 1949 FOREIGN PATENTS Number Country Date 697,675 France Nov. 4, 1930 

